Device for counting electrical impulses



eb 927 M. B. RICHTER DEVICE FOR COUNTING ELECTRICAL IMPULSES Filed March 10. 1926 Fig.4.

Fig.5.

Patented Feb. 1, 1927.-

MOBTEN BALTHAZAB RICHTER, OF COPENHAGEN, DENMARK.

DEVICE FOR COUNTING ELECTRICAL IMPULSES.

Application filed March 10, 1926, Serial No. 93,628, and in Sweden September 80,1925.

The present invention relates to a device for counting, which device is provided with co-axial numeral wheels and is particularly well suited for use as a. .telephone conversation counter, but which may also be used for other similar purposes. This counting device distinguishes itself by its compact construction and its small outer proportions, which particularly are advantageous by the use of the invention in telephone conversation counters, since a very high number of such counters often are to be arranged in close relation to each other within a confined or limited space.

The present counting device in its adaptation to a telephone conversationindicator contains an electromagnet controlled by the impulses to be counted and an armature for said electromagnet which may be connected in a suitable manner to the numeral wheel of the lowest order. The most essential feature of the invention consists in the particular manner in which the motion is transferred further from this wheel to the numeral wheel of the next higher order. In accordance with the invention a worm connected with the first named numeral Wheel and a gear wheel (or a toothed rim) connected with the other numeral wheel both engage a common rotatable transfer member which is constructed partly as a gear wheel and partly as a worm. 'Such a transfer device, being previously known per se, has not heretofore been used in counting devices and more parsistance against the turning movements of ticularly not in electric counting devices of the type indicated above, and the use of the same in such electric counting devices presents essential advantages, as there is not only obtained a simple and compact arrangement, but in addition hereto the counting device gets a practically constant rethe numeral wheels quite irrespective of their accidental positions, which effect it has not heretofore been possible to obtain by simple means in counting devices with co-axial numeral wheels. By employing the said transfer device in electric counting devices, such as telephone conversation counters, the sensibility of the apparatus thus becomes invariable and at the same time by constructing the numeral wheels as drums provided with graduations on the circun'iference the advantage is obtained that the indications of both numeral drums due to the co-axial mounting of the drums can conveniently be the front side of the apps.-

.fer device is particularly wellsuited for ver high ratios of gearing.

n accordanceiwith another feature of the inventlon the said transfer member maybe carried by a swingable shaft and normally by means of a spring kept in engagement with the worm and the gear wheel on the respective numeral wheels, so that by swinging the shaft by hand, thereby overcoming the force of the spring, the transfer member may be disengaged from the worm or the gear wheel or both when one or the other of the numeral wheels or both are to be rapidly adjusted in the zero positions.

Other features of the'invention will appear from the following description of the embodiment shown by way of example on the accompanying drawing.

F'gure lshows a side view of a telephone conversation counter constructed in accordance with the invention, one of the numeral drums and the magnetizing coil of the electromagnet having being remoyed,

Figure 2 is a partial section and front view of both numeral drums with associated transfer device, F gure 3 1s a slmilar-view, in which the transfer member is shown in partially disengaged position,

ing evice,

Figure '5 is a side view of the counting-- device corresponding mainly to Figure 1 with" the exception, that the transfer member is shown in partially disengaged position,-

and

Figure 6 shows a top view of the counting device.

The mechanism of the conversation counter i1- Fi ure 4 is a front view of the same countelect-romagnet and the counting.

lustrated on the drawing are mounted upon a frame or carrier consisting of a side plate 1 having a rear wall 2 and a-front wall 3,

and the said parts can be surrounded by a thin removable casing (not shown) having U-shape and which from one side may bev inserted over the parts of the apparatus. On the wall3 there is secured a thin front plate 4. The magnetic circuit of the electromagnet comprises an iron core 5, on the ends of which rear and front plate-shaped pole shoes 6 and 7 are respectively arranged, and a substantially rectangular plate armature 8 lying approximately in a horizontal plane parallel to the iron core and the hindmost end of which, Figure 1, is loosely inserted into a slot 9 in the uppermost part of the pole shoe 6. The armature thus may rock around its rearmost end. It is pressed into the said slot by means of two helical springs 10, the foremost end of each spring being connected with the armature while the rearmost end of the spring is hooked to a threaded stud 11 rotatably mounted in the pole shoe 6 or some other stationary part of the apparatus, so that by rotating this stud the corresponding end of the spring may be displaced upwardly or downwardly on the stud 11, whereby the tension of the spring can be adjusted. Hereby a very fine control of the sensitiveness of the electromagnet can be obtained inasmuch as the springs on account of their inclined positions not only keep the armature in position in the slot 9 but also normally press it against an adjustable stop screw 12, the springs thus serving as so called counter springs for the armature. The magnetic circuit formed by the iron core, the pole shoes 6 and 7 and the armature 8 has a very small magnetic reluctance.

The armature by its motion by means of the device hereinafter described, effects a step by step rotation of two numeral drums 14 and 15 which are freely rotatable upon a common stationary stud of shaft 13; these drums are partially visible from the front through a pane of glass or the like inserted in an opening 16 in the front wall of the apparatus as shown in Figure 4. The numeral drums are provided with graduated scales on the circumference. and the indications of the same can be read off at a mark 17 on a fixed web 18. 19 designates a number disc indicating the number of the subscriber in question. i

The armature 8 at one side is provided with an upwardly directed arm 20, Figure 1, on which is secured a spring pawl 21 engaging a toothed rim or ratchet wheel 22 on the numeral drum 14. 23 is a spring counter pawl. The numeral drum 14 is rigidly connected with a worm 24 normally engaging a toothed transfer member 25 which is carried by a rotatable shaft 26- and normally engages a gear wheel 27 secured upon the numeral drum 15, see Figure 2. This transfer member is constructed partly as a worm wheel (screw wheel) for engagement with the worm 24 and partly as a toothed gear for engagement with the gear wheel 27 the teeth of the transfer member for this purpose forming partly elements of a toothed gear wheel with high pitch as indicated by the line a in Figure 5 and partly elements of a worm or screw with small pitch as indicated by the line b. The said transfer member 25 thus presents the combined properties of two screw wheels having widely different pitches. It will be understood from the above explanation that the shaft 26 rotates at a lower velocity than that of the numeral drum 14 and that the numeral drum 15 in turn rotates more slowly than this shaft. The ratio of gearing between these two numeral drums for instance may be 1: 100.

It very often is considered a valuable advantage that telephone conversation counters are so constructed that it can be easily and rapidly ascertained whether any of the subscribers have carried on a number of conversations not far from a predetermined number or whether this last named number has been exceeded by any of the subscribers without it being necessary to frequently and accurately read off all of the conversation counters. Bv the apparatus shown on the drawing such a control can be effected by means of a signal member 29 rotating with the drum 15 but adjustable relative to the same. This signal member for instance comprises an angularly adjustable indicato spring 29 inserted below a head 28 formed on the end of the stud or shaft 13. Figure 2. This indicator spring yieldingly engages the side face of the drum and is rotated by the latter with a certain amount of friction. This indicator spring 29 which may be turned by hand relatively to the drum. is provided with a pointer 30 pointing at the graduations of the drum, and this pointer may be adjusted in a position oppo ite to the graduation corresponding to the predetermined number of conversations. As soon as this pointer becoms visible behind the pane in the front plate 4 it is hereby indicated that the number counted by the counting device is not far from the said predetermined number. The pointer 30 mav advantageously have a colour difiering widely from that of the circumference of the drum.

The engagement of the pawl 21 with the toothed rim 22 is insured bv a lug 31 on an arm 32, the uppermost end 33 of which abuts against a rigid transverse wall 34. The arm can be swung somewhat around this end 33. whereupon it can be clamped in position by a. screw 35. The said lug 31 prevents the numeral drum 14 from being turned accidentally, because when the pawl is in the inactive position the lug prevents the pawl from being pressed outwardly from the drum, and thus the pawl in turn holds the drum against rotation.

The shaft 26 carrying the transfer member 25 is mounted substantially parallel to the iron core 5 of the, electromagnet, and

this shaft is supported near its foremostend in-a fork shaped bearing 36 formed on a rigid member 37, while the shaft furthermore is jourualled in a' bore in a bearing plate 38 secured upon the transverse wall 34, this bore permitting the shaft to be swung somewhat in a vertical plane for the pur ose indicated below. The shaft is normal y pressed down into the bearin 36 by means of a helical spring'39 stretched between the shaft and the lower arm 40 of the said member 37, this spring 39 also serving to normally insure the pro er engagement between the transfer mem er 25 on one side and the worm 24 as well as the ear wheel 27 on the other, see Figures 1 an 2.

A complete mechanical feeding of the numeral drums can easily be effected from the front without dismantling the apparatus, and for this purpose a key 43, Figure 5, can be inserted into the right hand hollow end of'the shaft 26 through an opening 42, Figure 4, which is normally closed by a cover 41. When the shaft by means of the key is swung upwards from the position shown in Figure 1 to that shown in Figure 5 the member 25 is released from the worm 24 but still maintains its engagement with the gear wheel 27 as shown in Figure 3. The drum 15 then can be easily and rapidly adjusted into the zero position by rotating the key 43. If the right hand end of the shaft 26, Figure 5, by means of the key is swung still farther upwards the left hand end of the shaft through the intermediary of a stiff spring member 44 actuates the armature 8, so that the latter is depressed. When the key is thereupon released the springs 10 will raise the armature, and the pawl 21 will shift the numeral drmn 14. IV hen the shaft;

26 in this manner is completely lifted and released sei'eral times the armature thus is moved in the same manner as if it was attracted magnetically. Thus it will be understood that the numeral drum 14 in a mechanical way can be rapidly adjusted in the zero position or any other desired position.

The counting device might be so constructed that both numeral drums could'be shifted by hand after the raising of the transfer member, but the adjusting device described above and illustrated on the drawing is considered. more suitable.

()n the armature 8 is secured an insulating stud 45, Figure 1, which at each attraction of the armature closes a contact between two variable inactive position, so that a suitably high contact pressure is always obtained.

The closing of the contact as well as the operation of the pawl 21 can be inspected from the outside of the apparatus through windows 50 and 51 respectively inserted in the side plate 1 of the apparatus. 52, Figures 1, 5 and 6 are the terminals for the magnetizing coil of the electro-magnet and the set of contact springs 46, 47, and these terminals are carried through holes in the rear wall 2 and secured in slots in a disc 53 made of fibre. The whole apparatus can be clamped upon a suitable support by means of a clamping screw 54.

Various modifications of the embodiment described and shown on the drawing may be made without departing from the range and scope of the invention. Thus for instance the end of the shaft 26 might be extended out through an openin in the front wall of the apparatus, so that the shaft could be swung upwards and downwards and turned by hand without the use of a key or a similar implement. I

Having thus fully described my invention I claim as new and desire to secure by Let ters Patent: v

1. In a countin device, the combination of co-axial rotatab. e counter wheels, a worm associated with one of said counter wheels; a circular row of teeth associated with the other of said counter wheels, and a rotatable toothed transfer member engaging both said worm and said circular row of teeth and serving to transfer motion from the first-named counter .wheel to said second counter wheel, the teeth of said transfer member partly forming elements of a gear wheel and partly elements of a Worm.

In a counting device, the combination of a plurality of co-axial rotatablenumeral drums, means for driving one of said drums, and means includin a rotatable transfer member having teeti arranged in accordance with two substantially different pitches for transferring motion from said driven numeral drum to the other numeral drum.

3..In a counting device, the combination of co-axial rotatable counter wheels, one of said counter wheels being provided with a worm and the other one of said counter wheels being provided with a'circular. row

of teeth, means for operatingthe first-mew tioned counter wheel and a rotary shaft provided with a toothed transfer member engaging both said worm and said circular row of teeth and operating to transfer mo tion from the first-mentioned counter wheel to the second-mentioned counter wheel, said rotary shaft being journaled on a movable axis to permit the first-mentioned counting wheel to be released by. a movement of said toothed transfer member away from said worm.

4. In a counting device, the combination of a plurality of co-axial rotatable numeral drums, means for driving one of said drums, and means including a rotatable transfer member for transferring motion from the driven numeral drum to the other numeral drum, said transfer member having two sets of teeth of different pit-ch and meshing with sets of teeth 011 said numeral drums respectively.

5. A counting device comprising two coaxial counting, drums one of which is provided with a worm and the other with a gear wheel, means for imparting movements to the first-named counting drum, a rotary shaft. and a toothed transfer member carried by said rotary shaft and normally engaging both said worm and said gear Wheel for transferring motion from said firstnamed counter drum to the other counter drum. said shaft being mounted upon a shiftable axis whereby said toothed transfer member may be moved into and out of engagement with said worm.

(i. A counting device according to claim 5, in which the said rotatable shaft can be swung; into a position, in which the said transfer member is disengaged from the worm while still maintaining driving engagement with the gear wheel, whereby the counter drum associated with he latter may be adjusted by turning said shaft manually.

In testimony whereof I have atlixed my signature.

MORTFX BALTHAZAR RICHTER. 

